Question 1
A 68-year-old male patient with a history of atrial fibrillation has been prescribed apixaban to reduce his risk of stroke. The patient’s medical history also includes type 2 diabetes mellitus and hypertension. His current medications include metformin, lisinopril, and atorvastatin. Which of the following is an important counseling point for this patient?
A. Apixaban should be taken on an empty stomach to enhance its absorption.
B. The patient should monitor his blood pressure daily while on apixaban.
C. The patient should expect a greenish hue to his urine as a harmless side effect.
D. The patient should avoid over-the-counter NSAIDs without consulting a healthcare provider.
E. The patient needs to undergo regular INR testing to monitor apixaban’s effect.
Rationale: These drugs can increase the risk of bleeding, which is a significant concern for patients taking anticoagulants like apixaban. Unlike warfarin, apixaban does not require routine INR monitoring because it has a more predictable anticoagulant effect. Apixaban can be taken with or without food, making option A incorrect. Options B and C are not associated with apixaban therapy.
Question 2
Which of the following medications requires routine monitoring of aPTT to assess its anticoagulant effect?
A. Warfarin
B. Dabigatran
C. Rivaroxaban
D. Heparin
E. Apixaban
Rationale: This drug’s effect is commonly monitored using activated partial thromboplastin time (aPTT), especially when administered intravenously. Warfarin’s effect is monitored using INR, while dabigatran, rivaroxaban, and apixaban do not typically require routine coagulation monitoring due to their predictable pharmacokinetics and pharmacodynamics.
Question 3
A patient is transitioning from IV heparin to warfarin therapy for the treatment of deep vein thrombosis (DVT). Which of the following is the best practice for managing this transition?
A. Discontinue heparin immediately after the first dose of warfarin is administered.
B. Continue heparin for a minimum of 5 days and until the INR is therapeutic for at least 24 hours.
C. Start warfarin therapy only after stopping heparin for 48 hours.
D. Overlap heparin and warfarin therapy for exactly 3 days, regardless of INR values.
E. Increase the dose of heparin when starting warfarin to prevent clot progression.
Rationale: This is necessary because warfarin has a delayed onset of action and, initially, can promote a prothrombotic state by reducing protein C levels. Continuing heparin until the INR is therapeutic ensures adequate anticoagulation. Immediate discontinuation of heparin, waiting 48 hours after stopping heparin, or only overlapping for a fixed period without considering INR levels are not best practices for this transition.
Question 4
A patient with chronic kidney disease (CKD) stage IV is being evaluated for anticoagulation therapy due to newly diagnosed atrial fibrillation. Which of the following anticoagulants is most appropriate for this patient?
A. Apixaban
B. Dabigatran
C. Rivaroxaban
D. Edoxaban
E. Fondaparinux
Rationale: This drug is considered safe and effective for patients with CKD, including those with advanced stages, because of its lower reliance on renal clearance compared to other direct oral anticoagulants (DOACs) like dabigatran, rivaroxaban, and edoxaban. Fondaparinux, primarily eliminated by the kidneys, is less suitable for patients with severe CKD.
Question 5
A 55-year-old female patient is on warfarin therapy for atrial fibrillation. She has been stable on a dose of 5 mg daily. Her latest INR is significantly elevated at 6.0, with no signs of bleeding. Which of the following is the most appropriate initial action?
A. Administer vitamin K orally.
B. Increase the warfarin dose to correct the INR more rapidly.
C. Hold one or two doses of warfarin, then resume at a lower dose.
D. Administer fresh frozen plasma to reverse warfarin effect.
E. No action is required; recheck INR in 24 hours.
Rationale: For patients with an elevated INR but no bleeding, holding warfarin doses and then resuming at a lower dose is often sufficient to safely bring the INR back into the therapeutic range. Administering vitamin K orally is usually reserved for more significant elevations or if there is a bleeding risk. Increasing the warfarin dose or administering fresh frozen plasma is inappropriate and potentially harmful in this scenario without bleeding.
Question 6
Which of the following is a contraindication for the use of dabigatran in patients with non-valvular atrial fibrillation?
A. Age over 75 years
B. History of peptic ulcer disease
C. Mechanical heart valve
D. Creatinine clearance of 40 mL/min
E. Concurrent use of amiodarone
Rationale: This drug is contraindicated in patients with mechanical heart valves due to an increased risk of thrombosis and bleeding compared to warfarin, as demonstrated in clinical studies. Age, history of peptic ulcer disease, reduced renal function, and concurrent use of amiodarone are considerations for dose adjustment or increased monitoring but are not absolute contraindications.
Question 7
For a patient receiving enoxaparin for acute venous thromboembolism (VTE), which of the following laboratory parameters should be monitored periodically?
A. Prothrombin time (PT)
B. Activated partial thromboplastin time (aPTT)
C. Platelet count
D. Serum sodium
E. Blood glucose
Rationale: Monitoring platelet counts in patients receiving enoxaparin is important to detect heparin-induced thrombocytopenia (HIT), a serious adverse effect. PT and aPTT are not routinely monitored for patients on enoxaparin. Serum sodium and blood glucose levels are not directly affected by enoxaparin therapy and do not need to be monitored for this reason.
Question 8
A patient has been prescribed rivaroxaban for the treatment of deep vein thrombosis. Which of the following statements is true regarding the administration of rivaroxaban?
A. Rivaroxaban should always be taken with a meal to enhance its bioavailability.
B. Rivaroxaban can be crushed and mixed with applesauce for patients with swallowing difficulties.
C. Rivaroxaban doses greater than 15 mg should be taken on an empty stomach.
D. Rivaroxaban is only indicated for once-daily dosing, regardless of the indication.
E. Patients must fast for 6 hours before taking rivaroxaban to ensure absorption.
Rationale: This drug’s absorption is significantly increased with food, especially for doses of 15 mg and above, which are indicated for the treatment of DVT and PE and for the reduction in the risk of recurrence of these conditions. This increases its bioavailability and ensures therapeutic plasma concentrations are reached. The other options are incorrect representations of rivaroxaban’s administration guidelines.
Question 9
A 70-year-old male with renal impairment (CrCl 30 mL/min) is being considered for anticoagulation therapy with a direct oral anticoagulant (DOAC) for stroke prevention in atrial fibrillation. Which of the following DOACs is least appropriate for this patient?
A. Apixaban
B. Dabigatran
C. Rivaroxaban
D. Edoxaban
E. All are equally appropriate
Rationale: This drug renal clearance is higher compared to other DOACs, making it less suitable for patients with significant renal impairment (CrCl <30 mL/min) for stroke prevention in atrial fibrillation. While dose adjustments or careful consideration is required for all DOACs in renal impairment, dabigatran poses a higher risk of accumulation and adverse effects in these patients.
Question 10
Which of the following is true regarding the reversal of anticoagulation for a patient taking apixaban who presents with a life-threatening bleed?
A. Administer vitamin K 10 mg intravenously.
B. Use of protamine sulfate is recommended.
C. Andexanet alfa can be used as a reversal agent.
D. Fresh frozen plasma is the first-line treatment.
E. No reversal agents are available for apixaban.
Rationale: This drug is a specific reversal agent for factor Xa inhibitors like apixaban and rivaroxaban in the case of life-threatening bleeding. Vitamin K and protamine sulfate are not effective reversal agents for apixaban. Fresh frozen plasma is generally not considered the first-line treatment for reversing the effects of direct oral anticoagulants.
